Method and system for using air gaps in hot-stamping tools to form tailor tempered properties

ABSTRACT

A sheet metal blank is hot-stamped between first and second tool surfaces of first and second die tools, respectively, to form a hot-stamped product. That product is then heat treated between the first and second tool surfaces. An actively cooled portion of the tool surfaces quenches part of the hot-stamped product to form a hardened zone. An actively heated portion of the tool surfaces slows heat transfer from the hot-stamped product to the heated portion, which causes the hot-stamped product to have a soft zone. A matrix of insulating gaps is formed in the heated portion to further slow the rate of heat transfer from the hot-stamped product to the heated portion. The insulating gaps may facilitate the use of a lower-temperature heated portion, which may consequently save energy and result in the heated portion having greater wear resistance and longer life.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalPatent Application No. 62/805,232, filed on Feb. 13, 2019, which ishereby expressly incorporated by reference in its entirety.

BACKGROUND 1. Field of the Invention

Various embodiments relate generally to a hot forming system and methodfor producing vehicle parts.

2. Description of Related Art

Vehicle manufacturers strive to provide vehicles that are increasinglystrong, light and inexpensive. One process used to form vehicle bodyparts is a hot-forming method in which heated blanks of steel arehot-stamped and quenched (for rapid cooling and hardening) in a hotforming die. A pre-heated sheet stock may be typically introduced into ahot forming die, formed to a desired shape and quenched subsequent tothe forming operation while in the die to thereby produce a heat treatedproduct. The known hot forming dies for performing the stamping andquenching steps typically employ water cooling passages (for circulatingcooling water through the hot forming die) that are formed in aconventional manner. In some applications, it may be desirable to coolcertain portions of the stamped metal at a slower rate than otherportions. Such portions of the stamped part are heated by the stampingdie so that the rate of cooling is slowed relative to the portions ofthe part that are exposed to portions of the die that receive coolingfluid. The more slowly cooled portions of the part will remain softer(more ductile) than the portions of the part subject to rapid cooling(quenching). To heat portions of the die, cartridge heaters can beprovided within a form block of the die so that heat is applied to areasof a product being stamped.

SUMMARY

One or more non-limiting embodiments provide a hot-stamping apparatusand hot stamping method through which a sheet metal blank is hot-stampedbetween first and second tool surfaces of first and second die tools,respectively, to form a hot-stamped product. That hot-stamped product isthen heat treated between the first and second tool surfaces. Anactively cooled portion of the tool surfaces quenches part of thehot-stamped product to form a hardened zone. An actively heated portionof the tool surfaces slows heat transfer from the hot-stamped product tothe heated portion, which causes the hot-stamped product to have a softzone. A matrix of insulating gaps is formed in the heated portion tofurther slow the rate of heat transfer from the hot-stamped product tothe heated portion. The insulating gaps may facilitate the use of alower-temperature heated portion, which may consequently save energy andresult in the heated portion having greater wear resistance and longerlife.

The below-listed claims disclose additional non-limiting embodiments.

One or more of these and/or other aspects of various embodiments, aswell as the methods of operation and functions of the related elementsof structure and the combination of parts and economies of manufacture,will become more apparent upon consideration of the followingdescription and the appended claims with reference to the accompanyingdrawings, all of which form a part of this specification, wherein likereference numerals designate corresponding parts in the various figures.In one embodiment, the structural components illustrated herein aredrawn to scale. It is to be expressly understood, however, that thedrawings are for the purpose of illustration and description only andare not intended as a definition of the limits of the invention. Inaddition, it should be appreciated that structural features shown ordescribed in any one embodiment herein can be used in other embodimentsas well. As used in the specification and in the claims, the singularform of “a”, “an”, and “the” include plural referents unless the contextclearly dictates otherwise.

All closed-ended (e.g., between A and B) and open-ended (greater than C)ranges of values disclosed herein explicitly include all ranges thatfall within or nest within such ranges. For example, a disclosed rangeof 1-10 is understood as also disclosing, among other ranges, 2-10, 1-9,3-9, etc. Similarly, where multiple parameters (e.g., parameter C,parameter D) are separately disclosed as having ranges, the embodimentsdisclosed herein explicitly include embodiments that combine any valuewithin the disclosed range of one parameter (e.g., parameter C) with anyvalue within the disclosed range of any other parameter (e.g., parameterD).

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of various embodiments as well as otherobjects and further features thereof, reference is made to the followingdescription which is to be used in conjunction with the accompanyingdrawings, where:

FIG. 1 is a perspective view of a lower die of a hot stamping system;

FIG. 2 is a perspective view of a hot-stamped product manufactured bythe hot stamping system in FIG. 1;

FIG. 3 is a perspective view of a heated portion of the lower die inFIG. 1;

FIG. 4 is a top view of the heated portion shown in FIG. 3;

FIG. 5 is an enlarged top view of the portion 5-5 in FIG. 4;

FIG. 6 is a cross-sectional view of the heated portion of the lower diein FIG. 5, taken along the line 6-6 in FIG. 5;

FIG. 7 is a cross-sectional view of the heated portion of the hotstamping system in FIG. 1;

FIG. 8 is an enlarged cross-sectional view of the portion 8-8 shown inFIG. 7; and

FIG. 9 is a further enlarged cross-sectional view of FIG. 8.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

This disclosure relates to a hot-stamping system 10 and method forproducing a hot-stamped product 20 with tailored properties. Suchhot-stamped products 20 may include a vehicle body member or panel, or apillar of an automobile. Forming “tailored” properties of products orparts using the system 10 and method herein described provides shapedparts that have regions of high strength and hardness as well as otherregions of reduced strength, ductility, and hardness. When the hereindescribed forming system 10 is used as part of a method of forming sucha tailored product or part, such as vehicle pillars (A or B pillars),the resulting vehicle structure has a complex configuration thatincludes regions that are engineered to deform in a predetermined mannerupon receiving a force resulting from a vehicular crash, for example.

As shown in FIGS. 1 and 7, the system 10 comprises upper and lower dies30, 40 having upper and lower die tool surfaces 30 a, 40 a,respectively. FIG. 1 illustrates the lower die 30 and lower tool surface30 a. It should be understood that the upper die 40 and upper toolsurface 40 generally has a mating structure and surface. The upper andlower dies 30, 40 are shaped and configured to mate with each other toform a die cavity therebetween. The dies 30, 40 receive therebetween andhot stamp a workpiece/metal blank (e.g., a piece of hot sheet metal,e.g., steel such as press hardened steel (PHS), boron steel, with orwithout coatings (e.g., aluminum coating)).

As shown in FIG. 1, the lower tool surface 30 a is divided into heatedand cooled portions 50 a, 60 a. As shown in FIG. 1, the cooled portions60 a and heated portion 50 a may be formed by discrete die portions 60,50, respectively, of the lower die 30 that fit together to define theoverall die 30. FIGS. 3 and 4 illustrate the heated lower die portion 50that defines the heated portion 50 a of the lower tool surface 50 a.

As shown in FIG. 7, the heated die portion 50 of the lower die 30 (aswell as the corresponding heated upper die portion shown in FIG. 7)includes one or more heaters 70 that are positioned and configured toheat the heated tool surface portion 50 a. In the illustratedembodiment, the heater 70 comprise cartridge heaters, but couldalternatively comprise any other type of suitable heater (e.g., passagesthrough which heated fluid passes). The cooled die portions 60 of thelower die 30 (as well as the corresponding cooled upper die portions ofthe upper die 40) include one or more coolers (e.g., coolant passagesthrough which an actively cooled (e.g., via a refrigeration system)coolant flows).

In the illustrated embodiment, the upper and lower dies surfaces 30 a,40a in the heated portion 50 a of the dies 30, 40 are both heated.However, according to alternative embodiments, only the upper die 40 oronly the lower die 30 could be heated. Similarly, in the illustratedembodiment, the upper and lower tool surfaces 60 a in the cooledportions 60 of the dies 30, 40 are both cooled. However, according toalternative embodiments, only the upper die 40 or only the lower die 30could be cooled.

In the illustrated embodiment, the dies 30, 40 form one continuouscooled portion and one continuous heated portion. However, according tovarious alternative embodiments, additional and/or fewer heated and/orcooled portions may be provided to accommodate the particular hardnessand ductility requirements of any desired product (e.g., alternatinghard and soft portions of a work piece to provide an accordion crumplezone; a plurality of soft portions surrounded by a large hardenedportion, etc.).

As shown in FIGS. 3-9, a matrix 90 of insulating gaps 100 is formed inthe heated surface portions 50 a of the tool surfaces 30 a, 40 a of theupper and lower dies 30, 40. The matrix 90 divides the heated surfaceportion 50 a into (1) a non-contact surface area formed by theinsulating gaps 100, and (2) a contact surface area 110 where the gaps100 are not disposed. The contact area 110 is shaped and configured tocontact the blank during hot forming and contact the resultinghot-stamped product during heat treating. In contrast, the non-contactarea formed by the gaps 100 is shaped and configured to not contact theblank during hot forming and not contact the hot-stamped product duringheat treating.

As used herein, the area of any surface is its actual surface area.Thus, the depth and shape of the depressions that form the gaps 100 willslightly impact the area of the gaps 100.

As shown in FIGS. 6 and 9, the gaps 100 create depressions relative tothe contact area 110 surrounding the gaps 100. As shown in FIG. 6, thegaps 100 have a maximum depth d relative to the surface of the contactarea 110. According to various embodiments, the maximum depth d of atleast a D number of the air gaps 100 is (a) at least 0.01, 0.02, 0.03,0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5,0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and/or 5.0mm, (b) less than 20, 15, 10, 7.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0,1.5, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, and/or 0.2 mm, and/or (c)between any two such upper and lower values (e.g., between 0.01 and 20mm, between 0.05 and 1.0 mm, between 0.1 and 0.5 mm, etc.). According tovarious embodiments, the depth d is about 0.25 mm for at least 10 of thegaps 100. According to various embodiments, D is (a) at least 2, 3, 4,5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, and/or100, (b) less than 1000, 500, 400, 300, 200, 150, 100, 90, 80, 70, 60,50, 40, 35, 30, 25, 20, 15, 10, 9, 8, 7, and/or 6, and/or (c) betweenany two such values (e.g., between 2 and 1000, between 5 and 500, etc.).The depths d of different air gaps 100 may differ, even within a singleembodiment.

According to various embodiments, gaps 100 each have an area a as viewedin a direction perpendicular to the contact area 110 surrounding the gap100. According to various embodiments, the area a of an A number of thegaps 100 is (a) at least 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18, 19, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500,600, 700, 800, 900, 1000, 1250, 1500, 2000, 2500, 3000, 3500, 4000,5000, 7500, and/or 10000 mm², (b) less than 10000, 7500, 5000, 4000,3000, 2500, 2000, 1500, 1250, 1000, 900, 800, 700, 600, 500, 400, 300,200, 100, 90, 80, 70, 60, 50, 40, 35, 30, 25, 20, 19, 18, 17, 16, 15,14, 13, 12, 11, 10, 9, 8, 7, and/or 6 mm², and/or (c) between any twosuch upper and lower values (e.g., between 5 and 10000 mm², between 10and 1000 mm², between 15 and 200 mm², between 200 and 1000 mm²).According to various embodiments, A is (a) at least 2, 3, 4, 5, 6, 7, 8,9, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, and/or 100, (b) lessthan 1000, 500, 400, 300, 200, 150, 100, 90, 80, 70, 60, 50, 40, 35, 30,25, 20, 15, 10, 9, 8, 7, and/or 6, and/or (c) between any two suchvalues (e.g., between 2 and 1000, between 5 and 500, etc.).

As shown in FIGS. 4-5, the area a of an A number of the gaps 100 isgenerally rectangular, with the rectangular gaps 100 arranged in arectilinear grid of gaps 100. According to one or more embodiments andas shown in FIG. 5, the gaps 100 may comprise 20 m×20 mm squares on a 25mm pitch, which results in 5 mm wide contact surfaces 110 separatingadjacent gaps 100. As shown in FIGS. 3-4, others of the gaps 100 have anarea formed by different shapes. According to yet other embodiments, anarea a of an A number of the gaps 100 may have any other suitable shape(e.g., triangles or hexagons) and be laid out in any suitable matrix(e.g., a hexagonal or triangular grid, a matrix of mixed polygonal gaps100, a matrix of irregular gaps 100 having a variety of different shapesand areas).

According to various embodiments, a shape and size of the gap(s) 100 andcontact surface(s) 110 is chosen so as to the contact surface(s) 110 aresufficiently spread out over the heated portion 50 a that they supportthe blank during said hot-stamping and substantially prevent the blankfrom moving into the volume of the air gap(s) 100 during thehot-stamping. According to various embodiments, overlaying a circle witha diameter c onto anywhere within the heated portion 50 a results in thecircle overlaying at least a portion of the contact surface(s) 110.According to various embodiments, the diameter c is (a) less than 10000,7500, 5000, 4000, 3000, 2000, 1000, 900, 800, 700, 600, 500, 400, 300,250, 200, 150, 100, 90, 80, 70, 60, 50, 40, 30, 20, and/or 10 mm and (b)greater than 0, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30,35, 40, 45, 50, 60, 70, 80, 90, and/or 100 mm.

According to various embodiments, the cumulative contact surface 110area within the heated portion 50 may comprise at least (a) 20, 25, 26,27, 28, 29, 30, 31, 32, 33, 34, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80%of the area of the heated portion 50, (b) less than 20, 25, 26, 27, 28,29, 30, 31, 32, 33, 34, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80% of thearea of the heated portion 50, and/or (c) between any two such upper andlower values (e.g., between 25 and 80%, between 26 and 50%, etc.).According to one or more embodiments, the contact surface comprisesabout 36% of an area of the heated portion 50.

According to various embodiments, a surface area of the heated portion50 a (including both the contact surface area 110 and a surface area ofthe gaps 100) is (1) at least 100, 200, 300, 400, 500, 600, 700, 800,900, 1000, 1250, 1500, 2000, 2500, 3000, 4000, 5000, 7500, 10000, 15000,20000, 30000, 40000, 50000, 75000, and/or 100000 mm², (2) less than 100,200, 300, 400, 500, 600, 700, 800, 900, 1000, 1250, 1500, 2000, 2500,3000, 4000, 5000, 7500, 10000, 15000, 20000, 40000, 50000, 60000, 75000mm², and/or (3) between any two such upper and lower values (e.g.,between 100 and 100000 mm², between 200 and 20000 mm²). According tovarious embodiments, the surface area of the heated portion 50 a is thesame as the and surface area of the corresponding soft zone 20 a.

In the illustrated embodiment, each air gap 100 is isolated from everyother gap 100 by the contact surface 110. According to variousembodiments, each gap 100 is completely surrounded by the contactsurface 110. However, according to alternative embodiments, some or allof the gaps 100 may be interconnected (e.g., by a break in the contactsurface 110 that separates two adjacent gaps 100). According to someembodiments, such interconnection may result in isolated islands ofcontact surface 110 surrounded completely by one or more gaps 100 (e.g.,a matrix/grid of contact surfaces 110 separated by gaps 100, for exampleformed by reversing the relative positions of the gaps 100 and contactssurfaces 110 in FIG. 5).

According to various embodiments, the matrix extends over multiple gaps100 in orthogonal directions. For example, with respect to a matrixcomprising a rectilinear grid as shown in FIG. 5, the matrix creates arectilinear grid having x rows and y columns, where x and y are each atleast 2.

According to various embodiments, the gaps 100 each have a volume v.According to various embodiments, the volume v of a V number of the gaps100 is (a) at least 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400,500, 600, 700, 800, 900, 1000, 1250, 1500, 2000, 2500, 3000, 3500, 4000,5000, 7500, 10000, 12500, 15000, 17500, and/or 20000 mm³, (b) less than20000, 17500, 15000, 12500, 10000, 7500, 5000, 4000, 3000, 2500, 2000,1500, 1250, 1000, 900, 800, 700, 600, 500, 400, 300, 200, 100, 90, 80,70, 60, and/or 50 mm³, and/or (c) between any two such upper and lowervalues (e.g., between 20 and 20000 mm³, between 100 and 10000 mm³,etc.). According to various embodiments, V is (a) at least 2, 3, 4, 5,6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, and/or 100,(b) less than 1000, 500, 400, 300, 200, 150, 100, 90, 80, 70, 60, 50,40, 35, 30, 25, 20, 15, 10, 9, 8, 7, and/or 6, and/or (c) between anytwo such values (e.g., between 2 and 1000, between 5 and 500, etc.).

According to various embodiments, A, D, and V may be the same ordifferent from each other.

According to various embodiments, the gaps 100 may be formed by anysuitable manufacturing method, including, without limitation, materialremoval methods (e.g., machining/drilling/abrading the gaps 100 into thesurface of the dies), additive manufacturing (e.g., building up thecontact surfaces adjacent to the gaps 100 (e.g., via 3D printing) toform the gaps 100), casting or forging the gaps 100 into the surface ofthe dies (e.g., at the same time as the contact surfaces are formed, orthereafter), etc.

While the matrix of gaps 100 has been described in detail with respectto the lower die 30, it should be understood that a mirror-image (or nonmirror-image) matrix of gaps 100 may also be formed on the upper die 40,as shown in FIGS. 7-9. The corresponding portions of the upper die 40may also be heated via heaters. Similarly, portions of the upper die 40that mate with the cooled portions 60 may also be cooled.

As shown in FIG. 9, the matrix of insulating gaps 100 are shaped andconfigured to create a clearance between the hot-stamped product 20 andthe heated portions 50 a in the area of each of the insulating gaps 100during the hot-stamping and heat-treating. According to variousembodiments, the gaps 100 may be filled with air or another insulator(e.g., ceramic with a low heat conductivity). Consequently, the gaps 100slow heat transfer from the hot-stamped product 20 to the heated portion50 a.

The cooled portion 60 causes heat to quickly flow from the correspondingzone 20 b of the product 20 to the cooled portion 60 during theheat-treating, which results in quenching and the formation of ahardened zone 20 b (shown in FIG. 2) in the product 20.

While the heated portion 50 is heated, the temperature of the heatedportion 50 is still lower than the temperature of the blank/product 20when the hot-stamping process begins, which causes heat to flow from theproduct 20 to the heated portion 50 during the hot-stamping and, to agreater extent, during heat-treating. As a result, the heating of theheated portion 50 causes heat to transfer more slowly from thehot-stamped product 20 to the heated portion 50. Additionally, theinsulating gaps 100 slow the transfer of heat from the hot-stampedproduct 20 to the heated portion 50 via the gaps 100. Heating the heatedportion 50 and providing the matrix of insulating gaps 100, causes acorresponding zone 20 a of the hot-stamped product 20 that is pressedbetween the heated portions 50 of the die to be cooled relativelyslowly, which results in a soft zone 20 a of the hot-stamped product 20that is relatively softer and more ductile than the hardened zone 20 bof the product 20 and contains less martensite than the hardened zone 20b.

The rate of heat transfer from the hot-stamped product 20 to the heatedportion 50 is a function of the temperature gradient between the two.Heating the heated portion 50 reduces the temperature gradient, whichslows heat transfer and results in a softer, more ductile zone 20 a inthe product 20. However, increasing the temperature of the heatedportion 50 to reduce that gradient can be expensive due to energy costsand can detrimentally increase wear on the dies 30, 40 because hottertools wear more easily than lower temperature tools.

The heat transfer rate from the hot-stamped product 20 to the heatedportion 50 is also a function of the heat transfer coefficient of thegaps 100. The air gaps 100 provide insulation, which slows the transferof heat from the hot-stamped product 20 to the heated portion 50. Thisslowing of the heat transfer rate facilitates the counterbalancing useof a larger temperature gradient between the hot-stamped product 20 andheated portion 50, while still providing a soft zone 20 a. That largertemperature gradient means that the temperature of the heated portion 50can be lower, which reduces energy cost and increases the workinglifespan of the heated portions 50 of the dies 30, 40. According tovarious embodiments, the working lifespan of the heated portions 50 amay be extended by at least 5000, 10000, 15000, and/or 20000hot-stamping cycled between repair/resurfacing.

According to various embodiments, during the hot stamping and heattreating, a maximum temperature of one or more of the heated portions 50a of the tool surface (and/or a maximum temperature within the core ofone or more of the heated portions 50 of the die) is (a) at least 1, 2,3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85,90, 95, 100° C. cooler than a red hardness temperature of the toolmaterial that forms the heated portion 50 a and/or 50, (b) less than 10,20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300° C. cooler than a redhardness temperature of the tool material that forms the heated portion50 a or 50, and/or (c) between 1 and 300° C. cooler than a red hardnesstemperature of the tool material that forms the heated portions 50 aand/or 50, between 5 and 150 ° C. cooler than a red hardness temperatureof the tool material that forms the heated portions 50 a and/or 50,and/or between 10 and 100° C. cooler than a red hardness temperature ofthe tool material that forms the heated portions 50 a and/or 50.According to various embodiments keeping the heated portion 50 a of thesurface of the die 50 below (and preferably well below) its red hardnesstemperature will reduce wear and tear on the die portion 50, 50 a.According to various embodiments, keeping the core of the heated portion50 of the die below (and preferably well below) its red hardnesstemperature tends to reduce the thermal-expansion-caused deformation ofthe die (and resulting shape errors in the stamped part). Despite thisrelatively lower maximum temperature of the tool material that forms theheated portions 50 a, the air gaps 100 slow the rate of cooling of thehot stamped product sufficiently that the a hardness throughout theresulting soft zone 20 a of the heat treated product (i.e., uponcompletion of the heat treatment) is advantageously low, e.g., y,wherein y is (a) less than 400, 350, 300, 250, 240, 230, 220, 210, 200,and/or 190 Hv, (b) at least 100, 120, 140, 150, 160, 170, 180, 190, 200,210, 220, 230, 240, 250, 300, 350, and/or 400 Hv, and/or (c) between anytwo such values (e.g., between 100 and 400 Hv, between 140 and 300 Hv,between 150 and 250 Hv, between 180 and 220 Hv).

According to various embodiments, the blank material and cooled portion60 result in a hardened zone 20 b with a hardness, h, wherein h is (a)greater than or equal to 225, 250, 275, 300, 325, 350, 375, 400, 425,450, 475, 500, 525, 550, 575, 600, 625, 650, 675, and/or 700 Hv, (b)less than or equal to 700, 675, 650, 635, 600, 575, 550, 525, 500, 475,and/or about 450 Hv, and/or (c) between any two such upper and lowervalued (e.g., between 225 and 600 Hv, between 250 and 550 Hv, between350 and 600 Hv, between 400 and 550 Hv, etc.).

According to various embodiments, the tool material that forms theheated portion 50 a may comprise any suitable material: W360 steel,which has a red hardness of 580° C.; S600 with a red hardness of 610°C., Revolma with a red hardness of 630° C. There is a tradeoff betweenthe advantageous higher red hardness temperatures of tool materials suchas S600 or Revolma, and their correspondingly increased brittleness.

The foregoing illustrated embodiments are provided to illustrate thestructural and functional principles of various embodiments and are notintended to be limiting. To the contrary, the principles of the presentinvention are intended to encompass any and all changes, alterationsand/or substitutions thereof (e.g., any alterations within the spiritand scope of the following claims).

What is claimed is:
 1. A hot-stamping method comprising: hot-stamping ametal blank between first and second tool surfaces of first and seconddie tools, respectively, to form a hot-stamped product; and heattreating the hot-stamped product between the first and second toolsurfaces, said heat treating comprises: using an actively cooled portionof at least one of the first and second tool surfaces to form a firstzone in the hot-stamped product, and using an actively heated portion ofat least one of the first and second tool surfaces to form a second zonein the hot-stamped product, wherein the heated portion is heated by aheater that is thermally connected to the heated portion, wherein theheated portion comprises a combination of (1) one or more insulatinggaps that cumulatively define a non-contact surface area of the heatedportion, wherein the non-contact surface area does not contact thehot-stamped product during the heat treating and (2) one or more contactsurfaces that define a contact surface area of the heated portion andcontact the hot-stamped product during the heat treating, wherein theone or more insulating gaps slow heat transfer from the hot-stampedproduct to the heated portion during said heat treating, and wherein theheat treating results in a hardness throughout the second zone of lessthan y Hv, wherein y is 350 Hv.
 2. The method of claim 1, wherein amaximum temperature of the heated portion during said hot-stamping andheat treating is at least x° C. cooler than a red hardness temperatureof a tool material that forms the heated portion, wherein x is
 1. 3. Themethod of claim 2, wherein x is 25 and y is
 220. 4. The method of claim3, wherein the heat treating results in a hardness in the first zone ofat least 350 Hv.
 5. The method of claim 3, wherein the heat treatingresults in a hardness in the first zone of at least 400 Hv.
 6. Themethod of claim 3, wherein: the tool material comprises W360; and themaximum temperature of the heated portion during said hot-stamping isless than 600° C.
 7. The method of claim 1, wherein the heat treatingresults in a hardness in the second zone of less than 220 Hv and ahardness in the first zone of at least 400 Hv.
 8. The method of claim 1,wherein a maximum temperature in a core of the first and second dietools during said hot-stamping and heat treating is at least x° C.cooler than a red hardness temperature of a tool material that forms thefirst and second die tools, wherein x is
 1. 9. The method of claim 1,wherein: an area of the heated portion is at least 10000 mm²; thecontact surface area occupies less than 50% of the area of the heatedportion; and the contact and non-contact surface area is shaped suchthat overlaying a circle with a diameter c onto anywhere within the areaof the heated portion results in the circle overlaying at least aportion of the contact surface area, wherein c is less than 75 mm. 10.The method of claim 1, wherein the heat treating results in a hardnessthroughout the second zone of between 180 and 220 Hv.
 11. The method ofclaim 10, wherein the heat treating results in a hardness in the secondzone of at least 350 Hv.
 12. The method of claim 1, wherein theinsulating gaps each comprise air gaps.
 13. The method of claim 1,wherein the heated portion comprises a matrix of (1) said one or moreinsulating gaps or (2) said one or more contact surfaces.
 14. The methodof claim 13, wherein the matrix comprises a grid of (1) said one or moreinsulating gaps or (2) said one or more contact surfaces.
 15. The methodof claim 13, wherein: the heated portion comprises first and secondheated portions of the first and second tool surfaces, respectively; andthe matrix comprises first and second matrices formed in the first andsecond heated portions, respectively.
 16. The method of claim 1, whereineach of at least 5 of said insulating gaps occupies an area of at least20 mm².
 17. The method of claim 1, wherein each of at least 5 of saidinsulating gaps are at least 0.1 mm deep.
 18. The method of claim 1,wherein each of at least 5 of said insulating gaps have a volume of atleast 100 mm³.
 19. The method of claim 1, wherein, during said heattreating, active heating of the actively heated portion slows a transferof heat from the hot-stamped product to at least one of the first andsecond die tools.
 20. A hot-stamping system comprising: a first diehaving a first tool surface; a second die having a second tool surface,the first and second dies being configured to mate with each other sothat the first and second tool surfaces form a die cavity therebetweenso as to receive a metal blank therein and hot-stamp the metal blankinto a hot-stamped product; a cooler positioned and configured to cool acooled portion of at least one of the first and second tool surfaces; aheater positioned and configured to heat a heated portion of at leastone of the first and second tool surfaces; and the heated portioncomprises a matrix of (1) insulating gaps separated by contact surfaces,or (2) contact surfaces separated by insulating gaps, wherein theinsulating gaps are shaped and configured to create a clearance betweenthe hot-stamped product and the heated portion in the area of each ofthe insulating gaps after the metal blank is hot-stamped, wherein thecontact surfaces are shaped and configured to contact the hot-stampedproduct after the metal blank is hot-stamped, wherein the insulatinggaps are shaped and configured to slow heat transfer from thehot-stamped product to the heated portion.
 21. The hot-stamping systemof claim 20, wherein the insulating gaps each comprise air gaps.
 22. Thehot-stamping system of claim 20, wherein: the hot-stamping system isshaped and configured to heat treat the hot-stamped product between thefirst and second tool surfaces; the hot-stamping system is shaped andconfigured to use the cooled portion to form a first zone in thehot-stamped product during the heat treating; the hot-stamping system isshaped and configured to use the heated portion to form a second zone inthe hot-stamped product; and the first zone is harder than the secondzone.
 23. The hot-stamping system of claim 22, wherein the heatedportion is divided into (1) a non-contact area that is formed by theinsulating gaps and is configured not to contact the hot-stamped productduring said heat treating, and (2) a contact area that is shaped andconfigured to contact the hot-stamped product during said heat treating.24. The hot-stamping system of claim 22, the heater is positioned andconfigured to slow a transfer of heat from the hot-stamped product to atleast one of the first and second die tools during the heat treating.25. The hot-stamping system of claim 20, wherein the matrix comprises agrid.
 26. The hot-stamping system of claim 20, wherein each of at least5 of said insulating gaps occupies an area of at least 20 mm².
 27. Thehot-stamping system of claim 20, wherein each of at least 5 of saidinsulating gaps occupy a volume of at least 100 mm³.
 28. Thehot-stamping system of claim 20, wherein each of at least 5 of saidinsulating gaps are at least 0.1 mm deep.
 29. The hot-stamping system ofclaim 20, wherein: the heated portion comprises first and second heatedportions of the first and second tool surfaces, respectively; and thematrix comprises first and second matrices formed in the first andsecond heated portions, respectively.